The CrackGenerator ug4 app which uses the CrackGenerator ug4 plugin found here
ugshell -ex build_crack.lua
ugshell -ex build_crack.lua -width 2 -height 2 -depth 2 -spacing 1 -thickness 1 -h 1 -r_0 0.5
Parameters are width, depth and height which are self-explanatory. Spacing is the distance between the two bridging domain. The space between the two briding domains is the MD domain. Thickness describes the height of the bridging domains, r_0 is the lattice constant and h is a parameter to fine tune the element size, e.g. edge length of the elements.
ugshell -call BuildComplexCrack\(\);
